00262nam a2200121Ia 4500082002000000100002000020245002900040250000800069260003200077300002100109500000500130700000500135  a515.35bF699.DE  aFord, Lester R.  aDifferential equationsb  a2nd  aNew YorkbMcGraw-Hillc1955  axii, 291p. Index  a  a